THE OPINION OF AN EXPERT ON
MEUCCI'S PATENTS ON SICCATIVE OILS

by Prof. Luigi Cerruti (University of Turin)

In 1862 and 1863, Antonio Meucci obtained his two American patents on the preparation of hydrocarbon mixtures to act as solvents for paints. In those years, European researchers and technical experts were paying much attention to the American oil industry which was getting under way. Their interest was such that even single commercial products were studied at length by the best scientists. J. Wiederhold published between 1862 and 1863 a number of papers in which he analyzed the properties of a commercial product coming from the United States, which had been launched on the market as a substitute for turpentine. Thus, it is obvious that Meucci moved on the crest of the wave, as it were, in a very promising direction...

However, to fully comprehend their importance, one must bear in mind what E. Kopp, one of the most famous European experts, wrote in 1862: "It must not be forgotten that the exploitation, processing and transport of mineral oils is still carried out in a rather primitive way. It is an industry which is now taking its first steps, and which in effect is only two or three years old."

Thus Meucci was a pioneer also in this field.

MEUCCI'S PATENTS ON PAPER PULP MAKING, ASSESSED BY AN EXPERT TODAY

by Dr. Clemente Nicolucci (Favini Paper Manufacturing Co., Rossano Veneto, Vicenza)

With his three patents (1864, 1865, and 1866) Antonio Meucci is to be considered one of the innovators in paper making. He is indeed to be classified among the founders of the modern paper making industry. After the 1844 patent by Keller on mechanic pulp, Meucci's patents represent an anticipation, and allow one to foresee, in addition to bleaching, also the acid bisulfite process (Tilghman, 1867) and the sulfate alkaline process (Dahl, 1884), as well as the variations on the CTMP and semi-chemical pulps.

Unfortunately, as in the case of the telephone, he sowed well but what he harvested was even worse.

COMMENTS ON MEUCCI'S "EFFERVESCENT DRINKS" AND "SAUCE FOR FOOD"

by Dr. Roberto Merloni (STAR Food Industry, Agrate, Milan)

Foreword

On examining Meucci's patents filed respectively in 1872 and 1873, we have evidenced those aspects from which it clearly appears the connection of the author's creativity with the actual industrial realizations that have followed, up to the present time.

In doing so, it turns out a profile of an inventor endowed with a fertile mind, full of ideas and rich of intuitions, united to a deep knowledge of the field, and his ability of organizing it in theories, methods and schemes, suitable to be applied to productive processes, from artisan to industrial production.

Fruit Effervescent Drinks

Here Meucci employs fruit to confer its characteristic flavor to the drink. He utilizes both fresh fruit and dry fruit, the latter having the advantage of being easily preserved and retrieved in any period of the year. His process foresees the preparation of an extract, by reducing the dry fruit to fine particles that are then let in infusion on water. This is exactly the method that we use today, because the reduction to fine particles allows to increase the yield of the final product. We add the following comments:

• Extraction with water is now generally used for many vegetable products.
• Addition of gelatin makes the solid particles in the liquid suspension to precipitate and also leads to the clarification of the product. For example, modern processes to produce tea extracts employ gelatin to eliminate turbidity of the solution.
• Elimination of the solid part. The author proposes to use filtration for the fermented drinks, whereas for the other drinks he proposes decantation followed by aspiration of the liquid fraction from the top. The modern food industry generally uses filtration or centrifugation.
• Charge with carbon dioxide. The author uses "bottle soda", i.e. water saturated with CO₂, similar to the method widely employed today.
• Process for fresh fruit. The author employs the same process as above, with the only difference that fruit is "mashed" instead of being finely ground. The same process is followed today to the same end.
• Process for obtaining effervescent drinks through fermentation. The modernity of this method can be assessed by noting that many phases of this process are utilized in the production of beer, namely: the flavoring and boiling with hops; the filtering of wort, to separate solid residues; the fermentation with yeast; the charging with carbon dioxide to obtain a more sparkling drink.

Sauce for Pasta

We can note the following:

• Ingredients are the typical ones of the Bolognese ragout.
• Addition of gelatin is aimed to thickening the product and to confer a better capacity of seasoning.
• Though the method used substantially follows the classical tradition, the addition of lemon juice serves to acidify the product in order to guarantee its preservation through pasteurization in bain-marie. This expedient , together with the can filling (leaving little air space at the top of the can), is normally followed in modern industrial processes.
• Finally, we cannot but praise the author's suggestion to use trademark and detailed instructions in each can of the product.

TWO COMMENTS ON MEUCCI'S MILK TESTING METHOD

1. Meucci's Lactometer

by Dr. Piero Fantino (Milk Central, Turin)

Meucci, taking into account the composition of milk, resulting in a water content of average 88% and in milk-solids of about 12%¹, and having noted that those percentages remain unaltered with time, justly proposed a method for evidencing -- through an instrument of his own invention -- any eventual milk skimming and/or watering.

From the description of Meucci's apparatus it appears that his instrument is apt to ascertain the above adulterations.

Centrale del Latte di Torino

Dr. Piero Fantino,
Head of Milk Testing Laboratory

¹ In his patent specification, Meucci quotes these figures, and the relevant experiments made by the Swedish Royal Agricultural Society.

2. Meucci and the History of Milk Testing

by Prof. Sandra Carini (Experimental Institute for Milk and Diary Products, Lodi)

Around the end of the nineteen century, together with the development of transportation and the increase in demand of consumables, milk began to be produced on an industrial scale, as is today.

However, with the expansion of production, adulterations were also introduced by unscrupulous producers. This was particularly true in the United States, which were gaining, in those years, the rank of first food producers in the world.

For this reason, Dr. H. W. Wiley of Chicago began a scientific investigation on food adulteration, which was to last over 20 years, and ended up uncovering a scandal, given the vastness of the adulteration phenomenon detected. His research strongly represented, for the first time, the necessity of a legislation to fight food adulteration, based on official standards and methods of food testing (see the "Pure Food and Drug Act" of 1906).

Antonio Meucci's invention came into this picture well in advance of time, since, in 1875, it was aimed to determine the degree of genuineness or, more precisely, any milk adulteration arising from dilution of milk with water. Before Meucci, lacto-densimeters were used (e.g. Quevenne) . . . . which were far from solving the problem, given the difficulty -- then deemed insurmountable -- to separate and exactly evaluate by simple and practical methods the most variable part of the milk, i.e. the fat.

Meucci's lactometer bears, in this framework, a notable importance, not much for the precision of measurement (somewhat impaired by the use of strong reagents, liable to partly solubilize the milk-solids) but because it was a forerunner of the following, more sophisticated, methods of determining the fat contents of milk. We don't know how much Meucci's method was employed in the United States, but we must recall that his method was quoted by the founder of our Institute, Carlo Besana, in a note of 1886, dealing with the methods of milk testing¹.

Several years after Meucci's patent, Prof. Stephen Moulton Babcock of the Wisconsin University devised a simple and quick method for the precise dosage of fat in milk, that became a standard starting from 1890. . . . An improved (cryoscopic) method for determining the water content of milk was proposed by Winter, that became a world standard in 1902.

In conclusion, Meucci's invention mirrors an inquiring and ingenious mind, projected to the solution of impending problems of the time, presenting quite innovative aspects if framed in the historical moment in which it was conceived .

¹Meucci's Lactometer was constructed and sold in the United States by the firm "Tagliabue Optical Instruments" of Brooklyn, NY. Giuseppe Tagliabue was the owner of Meucci's patent.

AN EXPERT COMMENT ON MEUCCI'S HYGROMETER

by Prof. Vincenzo Ferro (Dept. of Applied Physics, Polytechnic of Turin)

Meucci's hygrometer was of the absorption type, i.e. based on the absorption of water vapor by hygroscopic materials -- particularly organic materials of natural origin -- which indicate the variation of atmospheric humidity through their change of weight, dimensions, electrical conductivity or other physical or chemo-physical parameters.

Among the natural substances used in this type of hygrometers as sensors of the atmospheric humidity are: cotton, wool, silk or flax fibers, feathers, hairs, natural sponges, hay, wood, osseous or corneous materials, egg pellicle. The most popular material was degreased hair (Saussure, 1782), substituted today by modern organic and synthetic fibers. With the progress of technology, however, they have lost importance as sensitive hygroscopic elements, mainly because of their unsatisfactory reproducibility and also for want of knowledge of their mode of operation.

At Meucci's times, hygroscopic materials were used in form of strips of suitable length. Evaporation of humid air would cause variation in length, depending on the humidity content of the air, which is as larger as longer the strip. The strip was maintained in tension with one end fixed and the other elastically connected to the periphery of a pulley. The elongation or the shortening of the strip caused the indication of the value of the humidity on a graduated face by means of a pointer solidly connected with the pulley.

The hygrometer conceived by Antonio Meucci has the advantage of constituting an instrument of least encumbrance, because he substituted the strip with a spiral coil, free to wind or unwind according to the variation in the humidity of the air. The hygroscopic material was obtained from a whalebone in form of a strip with rectangular cross-section. The strip was wound upon a pivot pin, that allowed the spiral motion of the strip without friction. The upper surface of the helix was varnished with a waterproof substance, whereas the lower surface was left hygroscopic, thus increasing the resulting elongation by tension of the spring. The strip coil is fixed at one end, the other end bearing a pointer, whose rotation gave the indication of the value of the humidity, as a function of the spiral displacement of the helix.

Note: Professor Ferro's original comment included an extended treatise on the History of Hygrometry, with particular reference to Meucci's times, not reported here for brevity.

OPINION OF AN EXPERT ON MEUCCI'S PATENT "PLASTIC PASTE"

by Dr. Gianfranco Ferrari, Director of Research & Development, Istituto Donegani-Enichem, Novara

This patent describes an original method for the preparation of a "plastic paste," suitable to be hot-poured into molds of various shapes and sizes in order to manufacture billiard-balls, statuary, vases, and objects of various kinds.

This patent can be seen today as an example of ingenious manipulation of the reagents forming the typical "chemical armamentarium" of the epoch, such as resins and natural solvents, starches, mineral and vegetable acids, cooked oil, as well as "fillers" (to confer consistency to the final product), composed of vegetable fibers or ground horn, ivory, bone, or mineral oxides or salts.

From the choice of constituents, but, above all, from their manipulation, it is evident that the result, though reflecting the empiricism of the epoch, is not reached by hazard, but through a non marginal knowledge of chemical processes as well as a valuable work of research and development.

A meaningful example, in this respect, is the preprocessing of vegetable fillers (illustrated in Meucci's previous patent of 1865), that the author employed towards obtaining a better adhesiveness. Even today the preprocessing of fillers in the production of reinforced and/or composite materials represents a delicate passage and is the subject of patents or proprietary know how.

Meucci's invention can be framed in the typical experimental activities of the epoch, aimed to the obtainment of artificial substitutes of some natural, but rare and expensive substances such as ivory, amber, tortoiseshell, horn, which were much demanded for their peculiar characteristics.

It must be taken into account that synthetic plastic materials were not available at the time (they will be introduced in the following century, the first being Bakelite, a resin obtained from formaldehyde and phenol, developed in 1909). The substances available to experimenters at Meucci's times were the many organic resinous substances such as asphalt, amber, India rubber, resins, proteins, starches and cellulose. Chemists and experimenters oriented their researches to both discovering the properties of those materials and how to use them, through modifications and manipulations, as a base for new materials or products, therefore called "artificial."

Along this line of research, Charles Goodyear discovers the process for vulcanizing rubber in 1839, giving rise to a flourishing industry, that, within a decade, consolidated both in England and the United States. In 1851, ebonite was obtained from rubber and found immediately a number of important applications, that are still in use today.

In 1868, John Wesley Hyatt developed celluloid (nitrocellulose plasticized with camphor), and shortly before (1865) the cellulose acetate was developed, which will become very important in the following century both as a fiber (rayon) and as a plastic.

Still in Meucci's time we can see the beginning of the first meaningful studies on the nature of natural resins and in 1880, thanks to Raoult and Van't Hoff, useful methodologies became available for the evaluation of high molecular weights, indispensable for the subsequent development of the macromolecular theories (Staudinger, 1920) as well of the chemistry of synthetic polymers, that would reach its first important achievements in the first three decades of the new century.

This was the context in which was born Meucci's invention, that was perhaps not fundamental to the technological development of the time, but was certainly meaningful as for the attention that Meucci gave to the main problems of his times, and indicative of his ingenious ability towards retrieving practical "solutions."

• Date last modified: 7 May 2003