At this point, however, it may be well to mention that the standard amount of proteid matter taken, in the construction of all these tables, was 130 grammes — 4.5 ounces. Moleschott's original diet-table contained only 120 grammes or (4.2 ounces), but as almost all observers agree quite closely as to the amount of proteid material necessary to be used, and also as to the results obtained from its oxidization, the same quantity was used in all instances that a more exact comparison might be established. The chief difference of dispute, however, is in relation to the relative value of the fats and carbohydrates, and particularly in reference to the latter compounds. 

In trying to develop out of a purely vegetable diet, anything like the same amount of working power for the system that is obtainable by the use of Porter's or Moleschott's diet, almost double the amount of proteid had to be taken with the proportionate rise in the fat and starch as is contained in the vegetable chosen. 

To produce the same amount of work by using a vegetable diet necessitates the outlay of a much larger amount of oxygen, and the production and handling by the glandular structures of the body of an excessive amount of the nitrogenous excrementitious elements. These facts illustrate quite conclusively the manner in which the damage to the system is brought about by indulging too freely, or living exclusively upon a cereal or vegetable compound. 

The vegetable proteid in these tables is further given an undue advantage, to which it is not justly entitled, by crediting it with the same atomic formula as that possessed by an animal proteid ; since the nitrogenous element found in plant-life contains a much larger number of nitrogen atoms, and consequently requires more vital force and oxygen to digest and assimilate it. This naturally decreases rather than improves the nutritive value of the proteid compound of vegetable origin. 

An average of a compound fat molecule is taken as the working standard in all these tables. 

Attention is also directed to a probable error in the rating of the heat-producing power of the carbohydrate. It is & commonly stated, that the comparative oxygenating capacity of a carbohydrate and fat is as one to two and one-half, but by their chemical atomicities, it is as one to thirteen, or thirteen and one-half in favor of the fat. 

That such an error exists in the computations in Moleschott's standard is sustained by a comparative study of the atomicities of the food-stuffs used in both Porter's and Moleschott's diet tables, and of the amount of oxygen required for complete oxidization in both instances. In the former, or Porter's proteid and fat diet table, a little more oxygen is needed than is necessary in Moleschott's mixed diet* yet it is claimed that in the latter instance 393,170 kilogramme-metres or 54,358 more foot pounds of work is produced. This, however, is directly opposed by the smaller quantity of oxygen used in the oxidization processes. When this error in work, produced out of the carbohydrates in Moleschott's diet, is corrected in accordance with the difference in atomicity and the amount of oxygen used between the fat molecule and the carbohydrate molecule represented as glucose, and a computation is made in accord with the correction, a slight difference in work produced when living on a Moleschott's or Porter's diet, is found to exist. The increase in work produced, however, is now found to exist in connection with Porter's diet and is in accord with the larger amount of oxygen used, which makes atomicity, oxygen used, and work produced correspond, while the reverse was stated in the calculations formerly made in connection with Moleschott's diet. 

If this error be true, as it appears to be, the profession have been sadly misguided in all their attempts in the construction of diet tables starting with Moleschott as their standard. 

On the other side, if these chemical and physiological laws be true, as based upon the atomicity of the proximate principles, by carefully considering the percentage composition of each food product to be used, exact results can be obtained. Another point to which attention is called by Dr. Porter is this, that the factors 1.812 and 3.841, which are used in computing the kilogramme-metres in Table VIII., are taken from Frankland — Philosophical Magazine XXXII., and are those which are generally quoted in all scientific works upon physiological chemistry and upon diet. 

In studying the proximate principles, however, by the atomicities, and considering the amount of oxygen required to completely transform a fat molecule into its final products of excretion water and carbon dioxide and a proteid molecule into its final products of excretion — urea, uric acid, kreatinine, carbon dioxide, water, etc. — it is found that only eighteen (18) more oxygen elements are used in the complete oxidization of the fat than in that of the proteid molecule. The computed amount of work performed by the oxidization of the fat molecule is found to be 530 foot pounds as compared to 250 foot pounds for the complete oxidization of the proteid molecule. This makes the eighteen (18) more elements of oxygen used in transforming the fat molecule result in the production of 280 more foot pounds of work than is obtained from the eighteen less used in the proteid. 

From this a decided discrepancy is quite evident between the results obtainable by former calculations and those based upon our modern chemical atomicities. 

However, for an illustrative and comparative study of the working power obtainable from the use of the various food-stuffs, this table is still of great value, as the same figures are used in each and all the calculations. 

As these same factors, 1.812 and 3.841, appear in all the modern scientific works, they were retained in the arrangement of this table, but not without appreciating and calling attention to this discrepancy when the computation is based upon the atomicities of the food elements used, the amount of oxygen required, and the results obtained. 

Again, it must be remembered that the proteids are not directly transformed into their final products, but undergo a series of intermediate changes, all of which require the use of oxygen and must of necessity yield more or less heat and energy, so that all our estimates are approximate. 

When upon Moleschott's diet with the proteid substances raised to the common standard of 130 grammes and the carbohydrates rated in accord with the correction previously noted, it requires 36,115 oxygen elements to produce 678,270 kilogramme-metres or 93,773 foot pounds of work. 

When upon Porter's diet of proteid and fat, it requires 38,415 oxygen elements to produce 734,890 kilogrammemetres or 101,602 foot pounds of work. When upon a purely vegetable diet that will yield anything like the requisite amount of work that can be obtained by using Moleschott's or Porter's diet, it requires 47,191 oxygen elements to produce 742,018 kilogramme-metres or 102,587 foot pounds of work. 

To obtain the 63,748 more kilogramme-metres or 8,814 foot pounds of work out of the vegetable diet as compared with Moleschott's diet, it requires the expenditure of 11,076 more oxygen elements. 

To obtain the 7,128 more kilogramme-metres or 985 foot pounds of work out of the vegetable diet as compared with Porter's diet, it requires the expenditure of 8,776 more oxygen elements. The vegetable diet in both instances yielding an excessive amount of nitrogenous excretory matter, carbon dioxide, and water. 

A careful study of Table II. and VII., and Porter's diet in Table VIII., proves beyond a question of doubt that upon an exclusive diet of our ordinary average meat alone very nearly the required proportions of the proteids or CHNOS compounds and of the fat or CHO element can be established. 

The only defect in the perfection of Table VII. and VIII. is found in the saline column, which contains much more mineral matter than perfect physiological laws indicate are required. This excess in saline or inorganic compounds, however, appears to be true in all kinds of food products — that is, if the proportion of salts in the milk is taken as the guide for a working basis. The reason for looking upon the amount of salts in the milk as the guide to the maximum quantity required is based upon the fact that during the infant period of life, where milk forms the only source of food supply, bone formation is most rapidly progressing, and the amount of mineral matter needed by the system is at its height and much larger than at any other period of life. The bones continue to grow and become fully and perfectly developed with the ordinary quantity of mineral matter contained in the milk. 

Physiology also teaches that a little less than one ounce of mineral salts are required daily by the system, but in all the tables given, except the one containing milk alone, the amount of salts is fully up to or more than an ounce. 

The only great objection that can be raised to an exclusive meat diet is the lack of variety, but that is quite easily adjusted by varying the kinds of meat used. The perfection of the proportionate composition of the proximate principles when using a meat diet, the smaller liability to imbibe an excessive quantity of any one kind and the little danger that there is of taking an excess of the CHO or stimulating and non-nutritious compounds, clearly establishes the fact that in meat we approach the nearest to an ideal food. 

If attention is turned for a single moment to the lower orders of the animal kingdom, it is quite apparent that the most supple and intensely powerful organisms are found among the carnivora only. This tends to substantiate the high utility of the meat diet. Another interesting point is the almost universal absence of tuberculosis among meat-eating animals, while the vegetable-feeding class are specially prone to suffer from this fatal malady.